Two-cycle engine.



E. J. WEBER.

TWO-CYCLE ENGINE. APPLICATION FILED ma. 14. 191s.

2 SHEETS-SHEET l.

Patented Jan. 2, 1917.

www.. /f y @y E. 1. WEBER.

TWG-CYCLE ENGINE.

Patentd Jan. 2,1917.

2 l@mitts-sain 2.

UNITED' STA 5 Two-cram ENGINE.

Specification of Letters Patent.

Application filed February 14, 1916. Serial No. 78,092.

, To .all 'whom t may concern:

Be it lmown vthat I, ELMER J. WEBER, a citizen of the United States, and resident of Oconomowoc, in the county of Waukesha and State of Wisconsin, have invented certain newl and useful Improvements in Two- Cycle Engines; and I do hereby declare that the following is a full, clear, and exact description thereof.

The present invention relates to new and useful improvements in two cycle internal combustion engines of that type including a cylinder having an inlet port in one end, a work piston and a scavenger piston disposed between the work piston and inlet port and provided with a valve controlled by-pass whereby upon reciprocation of the work piston, fresh gas will be drawn into the cylinder, .the scavenger piston being subsequently movable tov introduce fresh gas between it and the work piston whereby the gas is compressed for -explosion between the pistons upon inward movement of the work piston.

It is in general the object ofthe present invention to simplify the structure and improve the efliciency of engines of this type, and it is more particularly an object to provide an improved scavenger piston structure with respect to the mounting for the valve of the by-pass.

It is further anobject to 4provide an arrangement wherein the path of movement of the scavenger piston terminates short of the inlet port end of the cylinder, to thus provide a heating chamber for the fresh gases during and adjacent the time of explosion whereby a proper vaporization of the fuel .is facilitated.

A further object resides in the provision of an improved means for procuring reciprocation of the scavenger piston.

With the above and other objects and advantages in view, the invention resides more particularly in the novel combination, arrangement and formation of parts more particularly hereinafter described and particularly pointed out in the appended claim.

In the drawings: Figure l is a central longitudinal sectional view through a gas engine constructed in (accordance with the present invention and showing the relation of parts assumed in the initial position at the outset of the iring movement. Fig. 2 is a diagrammatic view vof the engine similar to the view shown in Fig. 3 and showing the relation of parts assumed at the end of the firing stroke. Fig. 3 is a view similar to Fig. 2 and showing the relation of parts assumed at the end of the. scavenging stroke of the scavenger piston. Fig. 4 shows the position at the beginning of the compression stroke.

Referring now more particularly to the accompanying drawings, 5 designates the water cooled cylinder of the engine which is 'open at its crank end in the usual manner and which has projecting laterally from its other closed end 'an Vintake chamber 6 provided in its bottom outwardly of the cylinder with -a valve seat 7 with which is associated the inlet valve 8. Slidable in the cylinder is the work piston 9 which is connected to the crank shaft 10 by the usual pitman 11, and an exhaust port 12 is providedin the side of the cylinder at a point immediately inwardly of the inner end of the -work piston when the work piston is at its outward limit of movement, a suitablev exhaust valve 13 being associated with this port. also in the engine cylinder between the work piston 9 and the closed end of "said cylinder is a scavenger piston 14 and the inner periphery of the cylinder adjacent its closed end is inwardly offset to form an annular seating shoulder 15 for the said scavenger piston at its limit of movement away from the work piston whereby the scavenger piston may firmly seat to form the end of the combustion chamber. It is noted that the work piston at its inner limit of movement is spaced from tlie scavenger piston in its above mentioned limit of movement whereby the space between these pistons holds the compression charge to be exploded, and to provide for explosion of this charge a chamber-16 is provided in the wall of the cylinder at this point and contains a spark plug member 17. l

For procuring a reciprocation of the scavenger piston upon each reciprocation of Slidable y the work iston, a stem 18 is slidably p through t e closed end ofthe cylinder and 'is connected with the scavenger piston vby' spider arms 19 andthis stem outwardly of the cylinder is toothed to provide substan` tially a gear rack portion which meshes with a segmental gear plate 20 rotatably mounted on a suitable support shaft 2 1 and this plate is vprovided withfa bowed slot 22 substantially in" the form ofya semicir'cle and en-r gaged in this slot is a crank pin23 carried on a shaft 24 which isl driven by the crank shaft 10 of the engine as at 25, the axis of the uslot being coincident-with the path of movement of the pin 23 whereby the inner side of the slot formscam surfaces' to procure a reciprocative movement of the plate `during a' respective half.' rotation of thev crank and one @ad oi. the inner edge 0f the slot beleg tiettened at 26 whereby movement of 'the crank pin thereover will Cause a more. even movement oi the plate vand eonsel qnently gf the scavenger valve stein. To permit a. flow of fresh or unused gas into the cylinder past the scavenger piston said piston is .provided with a central aperture. which is .normally closed by va valve 28 and adapted to seat in a depression in the inner MSO the scavenger piston, and having its 5139111' lida-bly mounted in a spider 29 in the said aperture, a spring 30 surrounding said Stem und normally urging the valve to clos-v ing position'.

For .simultaneously operating the inlet and exhaust valves, a single cam member 31 is provided on a shaft 32 driven by a chain 83 troni the -main crank shaft 10 and its cam member 31 carrying va'. single cam projection 34. which is adapted to engage and depress a valve rod connected With the valvesv 8 'and 18 by lever 36 und 3 7` respectively, it being noted that the intake valve moves vertically and the exhaust moves horizontally and consequently the iirst named lever is a straightlever and. the second lever is angular' in shape lalthough it will be understood that any desired arrangement or levers or valves i may be employed, the chief feature emphasized in the' present arrangement 1s that both valves will operate by a single cam member, and this cani member as yis more particularly shown by Figs. and 3 of the drawings operates during. the downward. move- ,'ment ofthe scavenger piston.

from its 'seat coindent wi 'forms "the hea Takingv up nowrthc operation of the en- 1 gine structure, it will 4be seen that'in f iring position shown more particularly in Fig. 1, the scavenger p y A u p of the combustion chamber.v

Upon firing, thework piston. movesfollt- `wai-:ily for a qlhiartcr rotation of the "shaft Upon t is quarter revolution being made, the scavengerfpiston toinove vaporization of the gas .isfacilitated v.by th'c sco embodiest ef'spvrt-ofyt (piston seatson its seat'land I pistonfcutwardlyo that end 'offthe pelled through the exhaust 'port at the same- 70 time thefresh charge of unused gas is drawn in behind vthe scavenger piston to fill the cylinder, vit being notedthat as thc scavenger piston projects past the inner 'edge' of the exhaust portat its limit of movementa prac-5 tically completeexpulsion` of burned gasesv' is procured. Upon the scavenger piston reaching this limit of movement the valves close and both pistons start their inward A movement, asfsho'wn in Fig. 3, itbeing noted 80 that the scavenger pistontravels faster than the work piston dueto .the cam arrangement ofthe slot 22, and the scaven `r piston com presses the unused s` in t e cylinder to suiiiciently force sai gas to overcome vthe spring holding means of the valve-28 and to pass into the outerportion of the cylinder between thetwo pistons, the work pis" toncontinuing to move inwardly to the initial firing position illustrated inlhEig, 1 and 90 toV procure a proper compression of the charge of gas between it and the scavenger piston. Thus it is noted that in the combustion chamber properthere is only one valve,

encountered. A stillfurtheradvanta c pro--1y00 cured from this' arrangement is a re uction of'surfa upon'which carbon is liable to form. A a considerable quantity-of unused gas under slight-compression is retained inthe end'of the cylindenbetween its 105 'i closed' extremity and the scavenger piston and -in thechamber 6 and'this quantity of gas receives a` considerable heat incident to operation of the engine-whereby the proper In the present drawing'sfand in the foregoing description I havedescribed the o erations and structureof my invention o yl in a general 'mannen and it will be understood -that in carrying out `the invention, 115 various modifications of structure. and op'- eration may ybe found expedient to liieet various conditions o'f andit is therefore understood-'that I am to be. onl

"of-the appended claim, whic '12o je invention.v I

I claim:A *1' f y -Anintefal combustione ,eofthecla'ss described includingfa-cylin er, awork :pis' ton thereinz fcrank'shaft cylindenja-stem exten from the'scav' I with 1215 vthe work Pimm-.a scavenger piston inthe cylinder farthest from the work piston, a have hereunto set my hand at Oconomowoc, pivoted plate in geaxmesh with the stem in the county of Waukesha, and State of and provided with an arcuate slot, a see- Wisconsin, in the presenoe of two wltnees. 11G

dnd shaft connected with the crank shaft, ELMER J, WEBER. 5 and a crank arm on 'the second shaft en- W'tnesses:

gaged in said slot. JOSEPH JOHNSON,

In testimony'that I claim the foregoing E W. F. WEBER. 

